Two weeks after riding his first Saturday city winner, apprentice Beau Mertens has struck again for the same trainer at Caulfield.

Mertens won on the John Salanitri-trained Hard Call on April 30 and was denied in a photo-finish aboard his stablemate Nat's The Boss on the same day.

Nat's The Boss made amends with a long head win in Saturday's Yellowglen Handicap (1200m), giving 18-year-old Mertens the third city win of his career while earning high praise from Salanitri.

"He listens. He rides to instructions and when he can't ride to instructions he uses his head," Salanitri said.

"It's very hard to get them like that, and I'm more than happy to have him riding for me."

Salanitri admitted Nat's The Boss, who has not missed a place in his eight career starts, has been a surprise package.

Saturday's victory was the three-year-old's first in town.

"I said to my staff a while ago, he's one of those horses that just slowly keeps sneaking up on me. I never thought he would get to this level, I must admit," he said.